Solar is quickly gaining interest among many property owners for being an inexpensive, clean source of energy. It works by converting sunlight into electrical energy through the use of solar panels.
While it’s common knowledge that solar panels generate electrical energy, many are unaware of how they work. Let’s take a closer look at what solar panels are made out of and the inner workings of these panels.
What Are Solar Panels Made Of?
Solar panels consist of various components and materials, each necessary to transform solar light into usable electricity.
Silicon Solar Cells
Each solar panel contains a semiconductor, a substance with electrons that are triggered when exposed to sunlight. The photovoltaic effect, which occurs when energized electrons move through a substance, generates an electrical current.
Today, approximately 94% of the photovoltaic modules in solar cells are made of silicon, with the remainder of the cells composed of materials such as:
- Cadmium telluride
- Copper indium gallium diselenide
- Organic compounds
Silicon is formed into a crystalline lattice, which provides a more structured arrangement for efficiently converting light to energy. The arrangement of silicon determines its efficiency and cost.
Melting a single silicon crystal forms monocrystalline cells, whereas polycrystalline cells are formed by melting numerous silicon crystals. Monocrystalline solar cells are purer and conduct energy more efficiently than polycrystalline solar cells.
A metal frame, typically made of aluminum, encases each solar panel. It shields the panel from the elements and makes installation easier.
A layer of glass between six and seven millimeters thick shields the silicon solar cells while allowing the maximum amount of sunlight to pass through. Insulation and a back sheet are installed behind the anti-reflective glass cover to prevent heat loss and humidity, both of which can reduce a solar panel’s performance.
A solar panel contains two types of wires: bus and 12V. Bus wires connect the solar cells, while 12V wires regulate the amount of electricity carried to the inverter to prevent overloading.
How Solar Panels Are Made
The manufacturing process for solar panels, especially ones consisting of silicon cells, is fairly standardized and streamlined to keep up with industry demand.
- To begin, manufacturers fabricate silicon cells by melting and purifying silica to metallurgical grade.
- Gallium or boron gets added during melting, enabling cells to conduct electricity.
- Silicon ingots are made and then sliced into thin sheets and coated with an anti-reflective coating.
- The silicon wafers get treated with phosphorus to give them a negative charge, which is necessary for the solar cell to operate more efficiently.
- Solar cells are stacked in a matrix-like pattern and soldered together to make a panel. The size of a panel depends on the number of solar cells; the industry standard is 60 solar cells. Commercial solar panels can have up to 72 cells, whereas smaller residential solar panels can have up to 48 cells.
- Following soldering, the manufacturer applies a protective back sheet composed of highly durable plastic.
- Glass covers the solar cells to filter the sunlight.
- An aluminum frame groups and secures everything.
- Ethylene-vinyl acetate binds all of the components together.
The junction box safeguards the wiring of a solar panel by preventing the reversal of electric flow while the panel is not producing power. Once installed, the manufactured solar panel is subjected to Standard Test Conditions.
The quality test ensures that each panel works and meets the manufacturer’s technical specifications. Panels spend time in a flash tester that simulates the following conditions: 1000W/m2 irradiance, 25 degrees Celsius cell temperature, and an air mass of 1.5g. The test reveals a panel’s power output, efficiency, voltage, current, and tolerance on impact and temperature.
When the solar panel passes the test, it is ready to be packed, shipped, and installed.
Are Solar Panels Environmentally Friendly?
Now that you know what a solar panel is made of, you’re probably wondering if their manufacture is environmentally friendly. As with other renewable energy sources, they come with an environmental cost—albeit a small one.
Solar panels have an average lifespan of 25 years, which means their environmental impact is spaced out during that period.
Learn More about Solar Panels
If you’re ready to make the switch and go solar, you need a trusted partner like Design 1 Solar Group to walk you through the entire process and educate you. We can tell you more about what solar panels are made of and explain in detail how they work to generate energy for your home.
Contact us today to find out more.